为了正确评价超燃发动机试验状态, 采用自发拉曼散射技术在线测量了超燃发动机流场的主要组分。基于发动机试验条件和发动机与光学诊断技术的接口, 建立了用于发动机流场组分测量的自发拉曼散射实验系统; 测量了多车次发动机试验过程中流场主要组分的拉曼光谱; 最后, 通过光谱计算获得了流场主要组分浓度信息并重点分析了来流氧气含量及其变化情况。实验显示: 发动机试验中, 部分车次试验补氧后的来流中氧气的最大含量达到了30%, 最小含量为18%, 说明发动机试验过程中, 对补氧量的控制精确和稳定性还有待提高。结果表明: 采用自发拉曼散射技术可以较好地完成来流主要组分浓度测量工作, 测量结果可用于发动机试验数据的分析及来流补氧控制方式和控制精度的改进。

To properly evaluate the experimental state of a scramjet engine, the Spontaneous Raman scattering technique was used to measure the main species in flow field of the scramjet engine. According to the engine experimental conditions and the interface of engine and optical diagnosis, a spontaneous Raman scattering experimental system for the engine flow field diagnosis was established. Then, the Raman spectra of the major species in the flow field of scramjet experiment were measured. Finally, the concentration of the major species was obtained by analyzing the Raman spectra, and the oxygen content of the incoming flow was emphatically analyzed. The results show that the maximum oxygen content and minimum oxygen content are 30% and 18% respectively in the incoming flow after oxygen supplementation. It means that the control precision and stability of oxygen supplementation in the scramjet experiment should be improved. The results also demonstrate that spontaneous Raman scattering technique works well for the species concentration measurements in the flow field, and obtained measurement results can be utilized for the analysis of scramjet experimental data and the improvement of the control method and control accuracy of oxygen supplementation for the incoming flow.